Self administration of gaseous anesthetics



May 31, 1938. J. GJSHOLES SELF ADMINISTRATION OF GASEOUS ANESTHETICS Filed Dec. 11, 1936 2 Sheets-She et 1 ATTORNEYS y 1938- J. G. SHOLES 2,119,446

SELF ADMINISTRATION OF GASEOUS ANESTHETICS Filed Dec. 11, 1936 2 Sheets-Sheet 2 g fit INVENTOR ATTORNEY Patented May 31, 1938 UNITED STATES PATENT OFFICE SELF ADMINISTRATION OF GASEOUS ANESTHETICS Application December 11, 1936, Serial No. 115,327 9 Claims. (01. 128-403) In many cases arising in the practice of medicine, surgery and dentistry, in which analgesia, that is relief from pain, is wanted rather than anesthesia, it is sometimes desirable to have the gas (or vapor) administered by the patient. Thus in parturition the patient knows best when the pain becomes too severe, and it is therefore of advantage to have the administration of the gas'under her control. Self-administration may also be advantageous in minor surgery such as the lancing of a boil or abscess, the cleaning and dressing of a wound or a burn, the setting of a fractured bone, or, in dentistry, the preparation of a tooth for filling.

It is accordingly an object of the present invention to provide a simple and convenient apparatus for the self-administration of a gaseous anesthetic, using this term hereinafter to include vapors as well as gases. Another object is to provide an apparatus in which the delivery of the anesthetic to the patient requires a purposeful efiort on the latters part, so that if by taking too much he or she should become unconscious or semi-conscious the supply of anesthetic will cease or will fall to so low a rate that he will speedily regain consciousness. A further object is to provide an apparatus in which the maximum amount of the anesthetic delivered by an actuation of the apparatus can be determined by the physician. Still another object is to provide simple and convenient apparatus which may be operated by the doctor to produce anesthesia, for example for the brief period needed in minor operaticns such as the lancing of a boil or abscess, setting a fracture or reducing a dislocation, probing a wound, removing skin blemishes, cleaning and dressing painful wounds and burns, etc., anesthesia for such purposes being particularly desirable in the .case of children. To these and other ends the invention comprises the novel features and combinations hereinafter described. In its broader aspects the invention comprises the combination of a source of anesthetic gas or vapor; an inhaling mask adapted to fit over the patients nose or over both mouth and nose, and in communication with the atmosphere so that at each inhalation air may be taken into the patients lungs; and between the mask and said source, control means to be operated by the patient, such means requiring positive, and preferably intermittent, operation by the patient, to deliver the anesthetic gas to the mask.

In the preferred form of the invention I provide a pump operated pneumatically by the patient, say by his hand or foot, and adapted for 'ing'a liquid from an atomizer nozzle) is shown connection with a suitable source of the anesthetic and with an inhaling mask of convenient shape to fit over the nose or mouth or over the nose and mouth of the patient. Connected with the mask I provide a chamber or reservoir, preferably composed in part of a flexiblc corrugated tube of suitable length, into one end of which air may be drawn at each inhalation and at the other end of which the pump is connected sothat the patient inhales a mixture of air and anesthetic.

Referring to the annexed drawings:

Fig. 1 illustrates one form of the invention, comprising a pump operated'by the patient, a mask, and a source of anesthetic; the source of the latter in the present instance being a rubber bag to hold a supply of the anesthetic inhalant.

Fig. 2 is a sectional view, on a larger scale, of a suitable pump, actuated pneumatically by the patient.

Fig. 3 is a part-sectional view illustrating on a larger scale than that of Fig. 1 the preferred air-gas reservoir.

Fig. 4 is a detail cross-sectional view of a simple form of check valve which may be used at the 2 air inlet of the/air-gas reservoir and at the mask.

Fig. 5 is a detailed sectional view showing the connection between the pump and the inhaling mask.

The bag I0, for holding a supply of the anesthetic inhalant, is connected to a head by which it may be connected with an ampule or cylinder or bottle containing the gas. The head shown at H is provided with a corrugated nipple l 2 over which a rubber tube, not shown, may be fitted, for temporary connection with a cylinder or bottle. The nipple may have a valve l3, which, when closed, will prevent escape of anesthetic into the air. A valve may also be provided, indicated at M, to control, and shut off entirely when desired, the outflow of anesthetic to the pump. A nipple I5 is shown for connection of the head II with the pump I6 by means of a rubber tube H. The pump is connected by a rubber tube It! to the mask 19, which latter may be of any suitable form and construction. The pump is actuated by a rubber bulb 20 which the patient can compress by hand. The bulb (preferably of the type commonly employed for sprayas connected to the pump by a rubber tube 2|.

bag or reservoir In large enough to hold sufficient anesthetic for a considerable range of operations on patients widely different in their susceptibility to the gas, but it will of course be understood that the doctor can put into the bag no more gas than his experience and judgment tell him will be needed. If the operation is to be performed at the patients home, for example, the doctor can take with him a small bottle or several ampules of the gas for replenishment of the supply in the bag as may be necessary. It is also desirable to have the bag as light as possible, so that even when it is well filled the gas therein will be under but slight pressure, but little above atmospheric at the most.

The pump, shown in detail in Fig. 2, comprises a hollow body portion or casing 22 divided into two chambers or parts by a transverse partition 23. Below the latter the casing has a nipple 24 for the tube l1 and a nipple 25 for tube I8, and may have check valves 26, 21, to permit flow of gas in the direction of the arrows only. These valves may be of any suitable construction, preferably with provision for adjustment to determine the pressure required to open them, and since check valves of such type are well known it is unnecessary to illustrate the construction of the same here.

The lower chamber of the valve body 22 is spanned by an elastic rubber diaphragm 28, held hermetically in place by a screw cap 29 equipped with a nipple 30 for the tube 2| leading to the hand bulb 20. Above the diaphragm is a plate or disk 3| carried by an adjustable stem extending through an opening in the septum 23.

From the foregoing it will be seen that if the bulb is compressed the air forced thereby through the tube 20 will expand the diaphragm '28, say to the position indicated by the dotted lines in Fig. 2, thus expelling gas and. any air present from the lower pump-chamber through check valve 21, the valve 26 preventing back-flow into tube l1. When the patient relaxes his hand the bulb expands, thus allowing the diaphragm 28 to collapse. As this occurs the check valve 21 closes grip the outflow of air through the vent will permit the diaphragm to collapse notwithstanding, and draw in a fresh supply of gas. However, to deliver more gas to the mask the patient must relax his pressure on the bulb and wait until it has expanded, more or less, by inflow of air through the vent or through the check valve (not shown) with which an atomizer bulb is usually provided. This has the advantage that i if his continued pressure on the bulb had been of a convulsive nature,due to his becoming unconscious or semi-conscious, he will not need more gas until he has regained consciousness far enough to feel the need and will then be sufllciently awake to remember to release the bulb.

The amount of gas that can be drawn into the pump chamber by collapse of "the diaphragm 28, and the amount that can be delivered to the mask I!) by the expansion of the diaphragm, is ordinarily determined with all necessary accuracy or closeness by the position of the plate or disk 3|, adjustable in position by means of. the

stem 33 to which it is connected. For the purpose of adjustment the stem is threaded in a disk or plate 34 threaded to the pump body 22 at a suitable distance from the septum 23. At its top the stem is rigidly attached to a rotatable member 35, so that by turning the latter the stem and the disk 3| can be adjusted toward or from the diaphragm. The member 35 may be in the form of a cup or cap, as shown, with its skirt or flange 36 extending down over the pump body and fitting the same closely enough to aid the ping on the floor or other rough usage. close fit will also give the cap suflicient frictional resistance to rotation to prevent unintentional alteration of the setting of the gas-volume plate or disk 3 If desired, the pump body may carry graduations, as indicated in Fig. 1, for example,-

to show, by the position of the edge of flange 36 as an index, the position of the volume-control disk 3|. The edge of the flange may be beveled for convenient reading. The graduations may be spaced to be read in any suitable units, as for example cubic centimeters or cubic inches. It will be seen that the pump serves not only to supply the anesthetic to the patient but also measures the amount so supplied as the bulb is compressed and that the amount can be varied as desired by the physician by a simple adjustment. v

To prevent leakage of gas along the stem 33 a yielding gasket- 31 may be provided, to be pressed against the stem by a neck 38 projecting from the disk or closure 34. I

The volume-control disk shown at 3| is formed to give free communication between the spaces above and below it. This may be done in various ways, as by making it smaller than the internal cross section of the pump chamber, or notching its edge at one or more points, or by perforating it, as indicated in Fig. 2.

By preference the tube |8,- leading from the pump I6, is not connected to discharge directly into the mask but is connected to an air and gas reservoir which is itself connected to the mask, through which reservoir the patient receives air for breathing, so that the gas which he takes into his lungs is admixed with air. The air and gas reservoir may comprise a simple tube 4| of the corrugated non-collapsible type, and a tubular elbow by which it is connected to the mask and to which the tube I8 is connected so that stem 33 'to resist breakage or bending by drop- A rather gas delivered to tube l8 by the pump will be discharged into the elbow; the other end of tube 4| being open to the atmosphere. Or the reservoir may include a light, easily 'expansible rubber bag 4|a enclosing the tube 4|, the latter having openings, as 4|b, for communication with the interior of the bag. At the discharge end of the elbow 40 is an inhaling check valve 42 and the mask is equipped with an exhaling check valve 43, so that 42 opens and 43 closes when the patient inhales, andvice versa when he exhales. If desired the outer end of tube 4| may be provided with a check valve to permit free inflow of air but prevent loss of the anesthetic gas from the air-gas reservoir through such end of the tube. A suitable valve for the purpose is shown in Fig. 4, comprising a septum 44 having an annular series of openings 45, and a thin rubber disk 46 fastened at its center to the septum or plate by a screw 41 so that at inhalation the disk will flex away from the openings 45 and thus admit air. The inhaling valve 42 at the elbow 40 may have a slightly higher tension than valve 46.

Then by continued pumping, more or less gas can be accumulated in the bag Ma without loss of gas through either valve, and this accumulation can be drawn upon by deep or vigorous inhalation. On the other hand, if the patient, getting more gas than necessary, becomes unconscious, or partly so, and ceases to pump, his continued breathing, even though light, exhausts the stored gas in the reservoir and thereafter he breathes air with no gas, or very little, until he begins pumping again. Either valve may be omitted but it is preferred to have at least one, and in some cases both are desirable.

It will be observed that what the patient takes into his lungs by inhalation when be squeezes the bulb is a mixture of air from the reservoir M-flla and gas from tube i8 leading from the pump l6, and that the maximum amount of gas in the mixture which can be so taken into the lungs is determined by the setting of an adjustable part or parts of the pump. It will also be observed that the patient can not draw gas from the elbow without drawing air therefrom also, and that the cross section of elbow 40 and chamber 4| is large in comparison with the size of the gas inlet on the elbow. Hence the suction of a sudden and powerful inhalation by the patient will, in general, be expanded chiefly upon the atmosphere through the reservoir 404l4l a, leaving but slight suction, if any, to be exerted on the check valve 21; so that by proper tensioning of the latter, or of valve 25, or both, the possibility of the patient drawing gas from the pump by inhalation alone can be eliminated, but still leaving itsufficiently easy for gas to be delivered through the supply tube i 8 by manual actuation of the pump.

The air and gas reservoir M, Ma, Mb, with its associated apparatus, as described above, is a part of my invention, and is believed to be novel and patentable per se; it is claimed in my copending application Serial Number 151,569, filed July 2, 1937, for Apparatus for self-administration of anesthetics.

It is to be understood that the invention is not confined to the construction herein specifically described but can beembodied in other forms without departure from its spirit as defined by the following claims.

I claim 1. Apparatus for the administration of an anesthetic, comprising, in combination, a source of anesthetic gas, a gas pump adapted to be operated by the patient and connected with said source for intermittent operation to receive gas therefrom, an inhaling mask for the patient, a reservoir connected with the mask and adapted to receive air from the atmosphere and deliver the same to the mask when the patient inhales, and a connection between the pump.and said reservoir for conveying gas to the latter when the pump is actuated whereby the patient when inhaling receives a mixture of air from the atmosphere and gas from the pump.

2. Apparatus for the administration of an anesthetic, comprising, in combination, a source of anesthetic gas, a gas pump connected with said source for intermittent operation to receive gas therefrom, pneumatic means adapted to be operated by the patient for actuating the pump, an inhaling mask for the patient, a reservoir connected with the mask and adapted to receive air directly from the atmosphere and deliver the same .to the mask when the patient inhales, and a connection between the pump and said reservoir for delivery of gas to the latter when the pump is actuated whereby the patient when inhaling receives a mixture of air from the atmosphere and gas from the pump.

3. Apparatus for the administration of an anesthetic, comprising, in combination, a source of anesthetic gas; an expansible pneumatic bulb adapted to be compressed by the patient for expulsion of air; a gas pump connected with said source and said bulb and having means for expelling gas when the bulb is compressed and drawing gas from said source when the bulb ex pands; an inhaling mask for the patient; a reservoir connected with the mask and adapted to receive air from the atmosphere and deliver the same to the mask when the patient inhales; and a connection between the pump and said reservoir for delivery of gas to the latter when the bulb is compressed whereby the patient when inhaling receives a mixture of air from the ,atmosphere and gas from the pump.

4. Apparatus for the administration of an anesthetic, comprising, in combination, a source of anesthetic gas; an inhaling mask for the patient;

a reservoir connected with the mask and adapted to receive air from the atmosphere and deliver the same to the mask when the patient inhales; a gas pump connected with the source of gas and with the reservoir for supplying gas from the former to the latter, the pump having a pneumatically actuated member movable in one direction to force gas to the reservoir and in the other direction to draw gas from said source; means for. predetermining the maximum amount of gas drawn from the source per actuation of said movable means; and a compressible and expansible pneumatic bulb connected with the pump to actuate said movable means by alternate compression and expansion of the bulb.

5. Apparatus for the administration of an anesthetic, comprising, in combination, a source of anesthetic gas; an inhaling mask adapted to be applied to the face of the patient; a reservoir connected with the mask and communicating with the atmosphere whereby air is'supplied to the mask for inhalation by the patient, said reservoir comprising a perforated non-collapsible tube in communication with'the atmosphere at one end and having its other end connected with the mask, and an expansible rubber bag surrounding the tube and communicating with the latter through the perforations therein; and a pump adapted to be operated by the patient, the pump being connected with the said source to receive anesthetic gas therefrom and with said reservoir to deliver gas thereto for admixture with air from the atmosphere to provide a mixture of gas and air for inhalation by the patient.

6. Apparatus for the administration of ananesthetic, comprising, in combination, a source of anesthetic gas; an inhaling mask adapted to be applied to the face of the patient; a reservoir connected with the mask and communicating with the atmosphere whereby air is supplied to.

the mask for inhalation by the patient, said reservoir comprising .a perforated non-collapsible tube in communication with the atmosphere at one end and having its other end connected with the mask, and an expansible rubber bag surrounding the tube and communicating with the latter through the perforations therein; and a pump adapted to be operated by the patient, the pump being connected with the said source to receive anesthetic gas therefrom and with said reservoir to deliver gas thereto for admixture connected with the mask and communicating with air from the atmosphere to provide a mixture of gas and air for inhalation by the patient, the pump comprising a member movable in one direction by the patient to receive into the pump a predetermined volume of gas from said source and in another direction by the patient to deliver gas to said reservoir.

7. Apparatus for the administration of an anesthetic, comprising, in combination, a source of anesthetic gas; an inhaling mask adapted to be applied to the face of the patient; a reservoir the other'side of the diaphragm therein for actuation by the patient to expand and contract the diaphragm.

8. Apparatus for the administration of an anesthetic, comprising, in combination, a source of anesthetic gas; an inhaling mask adapted to be applied to the face of the patient and having inhaling and exhaling check valves; a reservoir connected with the mask and communicating with the atmosphere whereby air is supplied to the mask for inhalation by the patient, said reservoir comprising a non-collapsible tube incommunication with the atmosphere at one end and having its other end connected with the mask; and a pump adapted to be operated by the patient, the pump being connected with the said source to receive anesthetic gas therefrom and with said reservoir to deliver gas thereto for admixture with air from the atmosphere to provide a mixture of gas and air for inhalation by the patient.

9. Apparatus for the administration of an anesthetic, comprising in combination, a source of anesthetic gas, an inhaling mask in communication with the atmosphere whereby tosupply air.

therefrom to the patient, a pump comprising a chamber connected with said source and 'said mask, and a member movable in one direction thereinto draw gas from the source into the chamber and in the other direction to expel gas from the chamber to the mask, said pump being connected with said source and the mask and operable by the patient to inject gas from said source into the air taken from the atmosphere into the mask, and means operable to predetermine the maximum amount of gas so injected when the'pump is actuated.

JUSTIN G. SHOLES. 

